Spatial and Temporal Patterns of Water Quality in Cullera Bay

Abstract

The Jú car River, characterized by a very irregular freshwater flow, discharges into the Spanish Mediterranean coastal waters. However, the flow at its mouth is usually insignificant due to the overexploitation of upstream water. Under normal conditions, the final stretch of the river (downstream from the Cullera weir) is nurtured only by water released from the weir and small discharges from lateral irrigation channels. During periods of heavy rain, however, a significant amount of water flows through the Cullera weir. An analysis of data acquired during several field campaigns in Cullera Bay clearly reveals a zonal distribution of nutrients and chlorophyll-a within the bay: a southern area of continental influence, located near the mouth of the Júcar River; a region affected by karst filtrations and minor freshwater inputs, located to the north of the bay around Cullera Cape; and a third zone in between, characterized by higher salinities. Spatial salinity distribution is indicative of the spatial distribution of some of the nutrients discharged by the river, particularly nitrite, nitrate, orthosilicic acid and total phosphorus (TP), since it has been shown that their behavior is inverse to that of salinity. However, neither soluble reactive phosphorus (SRP) nor ammonium, which are mainly affected by biological activity, show this type of behavior. Five different conditions/ scenarios were identified during the overall sampling period based on the time-series analysis of wind parameters, rainfall, freshwater flow, salt-wedge thickness at the measuring station on the river, and by comparing the average surface salinity at the sea stations with the values obtained at the coastal stations. ADDITIONAL INDEX WORDS:Nutrient, stratified estuary, Mediterranean Sea.

Chlorophyll a, nutrients and phytoplanktonic community in a continental ecosystem highly influenced by marine waters

“…At intermediate depths in the water column, the sedimentation of phytoplankton senescent cells affected by saline shock yield a secondary abundance maximum in the halocline. This phenomenon has also been detected in previous studies in the Júcar Estuary (Falco et al, 2007;González del Río et al, 2007 andRomero et al, 2007) and in the Ebro River Estuary (Falco, 2003).…”

“…The aim of this paper is to study two different environmental conditions that take place in the last kilometres of the stratified Júcar Estuary in the Mediterranean Sea, where it has been verified that these two alternative scenarios are repeated through time (Falco et al, 2007;González et al, 2007;Romero et al, 3 2007). In the first case, the river flow is continuous and significant and in the second one, the freshwater input is lower and discontinuous, due to surplus irrigation water: How these conditions are expected to affect phytoplankton composition?.…”

Caracterización bacteriológica y simulación con Visual Plumes en la descarga del emisario submarino de Gandía en la costa valenciana

“…Los resultados correspondientes a la caracterización bacteriológica del agua de mar se presentan en la tabla 1, con los valores máximos para los diferentes parámetros analizados. Una explicación más amplia de las campañas realizadas ha sido documentada en diferentes estudios llevados a cabo en la zona [3,4,5,6,7,8] Las concentraciones de bacterias coliformes fecales (CF), totales (CT) y enterococos (E) fueron comparados con el valor establecido por la Directiva Europea para aguas de baño que se encontraba vigente durante las campañas (Directiva de Consejo 76/160/CEE y el Real Decreto 734/1988) [9]. Los resultados se compararon con el valor obligatorio y guía que establece esta Directiva para aguas de baño (tabla 2).…”

Consequences of Anthropic Actions in Cullera Bay (Spain)

“…From the morphosedimentary perspective, the space considered is within a sedimentary dynamic that encompasses the entire southern sector of the Gulf of Valencia, which extends from the port of Valencia to the coast of Denia (Figure 1b). This longitudinal sedimentary transport dynamic is characterized, as in the rest of the gulf, by the existence of a coastal drift from north to south [23]. The sedimentary supply that reaches the studied coast comes from the fluvial contributions of the rivers that predominate in this sector: (i) The River Túria, which affects the beaches to the north of the Cape of Cullera, and which contributes sand in strong storms to the study beaches by circumventing the Cape; and (ii) the River Júcar, which covers the rest of the beaches [24].…”